APA (7th ed.) Citation

Sinclair, A. (1944). An introduction to philosophy / by A. Sinclair. O.U.P..

Chicago Style (17th ed.) Citation

Sinclair, A. An Introduction to Philosophy / by A. Sinclair. O.U.P., 1944.

MLA (9th ed.) Citation

Sinclair, A. An Introduction to Philosophy / by A. Sinclair. O.U.P., 1944.

Warning: These citations may not always be 100% accurate.